2011年2月第40卷第3期
施工技术
CONSTRUCTION TECHNOLOGY
深圳湾体育馆焊接合拢对结构受力性能的影响分析
郭彦林赵思远
（清华大学土木工程系北京
100084)
[摘要］焊接连接的杆件在焊缝冷却后会在杆件中产生残余变形与残余应力,其焊接构件的残余变形一般会受到周围构件的约束作用而转化为结构中的残余内力，这种在结构中新增的附加残余内力对结构受力性能极其不利基至使得部分杆件受压届服或受拉断裂而失效·首先研究了单个非约束自由构件的焊接收缩变形规律提出了收缩变形计算公式；其次提出了一种H形刚架模型通过对横梁实施对接焊研究焊接连接中焊缝尺寸、焊接顺序以及周边构件的约束强弱对H形刚架体系焊接成型状态的影响·最后以深圳湾体育场焊接合拢过程为研究对象通过
等收缩量原则将上述结果应用到体育场的合拢中指出焊接收缩对合拢缝周围杆件内力的影响不睿忽视。【关键词］体育馆；焊接；残余内力；等收缩量原则
[中图分类号】TU758.162
[文献标识码】A
[文章编号］1002-8498(2011) 03-0071-05
Welding Effects on Roof Closure Process of Shenzhen-wan Stadium
Guo Yanlin ,Zhao Siyuan
( Depariment of Civil Engineering Tsinghua Unirersity , Bejing 100084 , China)
Abstract: High residual stresses of members will lead to residual internal force and deformation in the structures when the member-welding is constrained by around members. This additional residual internal force in the structure may result in structural member yielding due to compression or cracking due to tension. The authors focuse on the effect of roof welding closure process of Shenzhen-wan Stadium. Welding shrinkage deformation of a single tube is studied firstly , and a proposed formula for predicting welding shrinkage deformation is drawn. Then a typical H-shaped frame model is proposed to investigate the effect of welding size and welding sequence of a single beam due to the constraint provided by adjacent members. The conclusion is drawn and is used in the roof welding closure process of Shenzhen-wan Stadium based on the equal welding deformation principle. Simulating results of the roof closure process indicate that internal foree of tubes in the nearby welding path due to welding shrinkage cannot be ignored.
Key words: stadium; welding; residual internal force; equal welding deformation principle
1
研究背景
采用焊接连接的构件在焊接冷却之后会形成较
高的残余应力对于完全自由的单个构件由于构件与周围构件没有约束作用所以焊接残余应力的大小虽然可能达到材料屈服强度但是对于单个截面而言残余应力的分布是自平衡的
残余内力与外荷载引起的结构内力相比主要有如下3点不同：①结构内力是由外荷载产生的而焊接残余内力是由结构内部某些杆件收缩变形受到约束产生的；②外荷载造成的结构内力与焊接残余内力都会在结构支座上形成支座反力但前者支座反
[收稿日期】2010-01-02
【作者简介］郭彦林清华大学土木工程系教授博士生导师北京 100084 ,电话: ( 010) 62796859 E-mail: syl@ mail. tsinghaa. edu. cn
万方数据
71
力总和等于外荷载而后者支座反力总和为零；③由外何载造成的内力大小以及变形取决于外何载大小何载越大结构内力以及变形越大：焊接残余内力的大小与周围构件对焊接构件的约束程度有关：约束越强残余内力越大但是残余变形越小反之约束越弱残余内力越小残余变形越大。
目前大型工程安装过程中往往特别重视对位形
的控制而忽视对内力的控制,在结构合拢阶段因为位形控制要求会对合拢处的杆件强制焊接拼装这相当于给连接杆件施加了很强的约束这样在结构合拢安装之后由于焊缝收缩在结构中形成很大的残余内力某些区域的残余应力可能使材料屈服甚至导致板材撕裂在结构中形成安全隐患
本文采用有限元的方法对焊接合拢过程进行数